Single-zone office building
[Commercial buildings (commercial)]

Detailed Description

The building simultion uses a single zone ETP model with first order ODEs:.

$T'_i = \frac{1}{c_a} \left[ T_m U_m - T_i (U_a+U_m) + T_o U_a + \Sigma Q_x \right]$

$T'_m = \frac{U_m}{c_m} \left[ T_i - T_m \right]$

where:

is the temperature of the air inside the building
is $\frac{d}{dt}T_i$
is the temperature of the mass inside the buildnig (e.g, furniture, inside walls etc)
is $\frac{d}{dt}T_m$
is the ambient temperature outside air
is the UA of the building itself
is the UA of the mass of the furniture, inside walls etc
is the heat capacity of the mass of the furniture inside the walls etc
is the heat capacity of the air inside the building
is the heat rate from internal heat gains of the building (e.g., plugs, lights, people)
is the heat rate from HVAC unit
is the heat rate from the sun (solar heating through windows etc)

General first order ODEs (with $C_1 - C_5$ defined by inspection above):

$T'_i = T_i C_1 + T_m C_2 + C_3$

$T'_m = T_i C_4 + T_m C_5$

where

General form of second order ODE

$p_4 = p_1 T"_i + p_2 T'_i + p_3 T_i$

where

Solution to second order ODEs for indoor and mass temperatures are

$T_i(t) = K_1 e^{r_1 t} + K_1 e^{r_2 t} + \frac{p4}{p3}$

$T_m(t) = \frac{T'_i(t) - C_1 T_i(t) - C_3}{C_2}$

where:

$K_1 = \frac{r_1 T_{i,0} - r_1 \frac{p_4}{p_3} - T'_{i,0}}{r_2-r_1}$
$K_2 = \frac{T_{i,0} - r_2 K_2}{r_1}$
is the elapsed time
is the temperature of the air inside the building at time
$T_{i,0}$ is , e.g initial temperature of the air inside the building
$T'_{i,0}$ is e.g the initial temperature gradient of the air inside the building

enum HCMODE

Enumerator:

HC_OFF	HVAC is off.
HC_HEAT	HVAC is heating.
HC_AUX	HVAC is supplemental heating.
HC_COOL	HVAC is cooling.
HC_ECON	HVAC is economizing.
HC_VENT	HVAC is ventilating.

Definition at line 33 of file office.h.


Enumerations
enum	HCMODE { HC_OFF, HC_HEAT, HC_AUX, HC_COOL, HC_ECON, HC_VENT }